The heart of the recession is actually three things:
1) Going to war
2) Cutting taxes
3) Borrowing from other countries to pay for it (selling T-bonds)

(1) isn't a problem if you raise taxes to cover the costs
(2) isn't a problem if you are reducing expenditure and have a growing economy
(1) and (2) together was the most idiotic thing any rational economist had ever heard of. It meant that (3) was necessary.

But (3) was the heart of the housing bubble. The Treasury had to generate a profit to cover the effective interest payable on the T-bonds. They gave the money to the banks with the order "get it out there and generating a profit". So the banks loaned it out, and with owning a house as a priority investment, it largely went into housing. Make more money - reduce the deposit necessary, attract borrowers to your bank so you can generate more profit. And we know the result.

The recession can be laid squarely at the feet of Bush's advisers. Not Bush himself, he's not supposed to know this stuff. Greenspan should have known, and although he blames the Bush administration, the bubble was created by his policies. (Strangely, his thesis, supposedly about easy credit and housing bubbles, was removed at his request.)
He can point to the instructions he was given, however, so he's definitely not entirely to blame.

Or you reverse the policies and leadership that led you into the bad years instead of tolerating them. Wallowing in economic despair and trying to make us comfortable at the bottom isn't our only option even if it's the only plan Obama has set forth.

Because the recession is Obama's fault, and Romney's strategies don't resemble in any way the causes of it.